Padgett arrived on the school bus on Tuesday, carrying a guitar case and a large duffel bag, Troutdale Police Chief Scott Anderson said at a press conference. One of those held an AR-15 rifle that the teen brought from home, the sheriff said.

"The weapons had been secured, but he defeated the security measures," Anderson said.

Jared Michael Padgett was identified by cops as the teenage gunman who killed a fellow freshman and wounded a teacher at Reynolds High School in Troutdale, Oregon, on Tuesday, June 10, 2014.Facebook

When the teen got off the bus, he entered school through the boys' locker room, housed in the building that holds the gym, Anderson said.

Gym teacher Todd Rispler was shot in the hip but still managed to get to safety and initiate the school lockdown procedures, Anderson said.

"I cannot emphasize enough the role that Mr. Rispler and the responding officers played in saving many many lives yesterday," the sheriff said.

After shooting Rispler and fleeing the locker room, Padgett then encountered responding officers in a hallway and, after an exchange of gunfire, fled into a restroom, Anderson said. He was later found dead of a self-inflicted gunshot wound, police said.

Oregon State Senate President Pro Tempore Ginny Burdick told NBC News she regrets that the state currently has no law that bans assault-style weapons nor is there any law that holds parents criminally liable.

"This is a public health catastrophe we have on our hands," Burdick said of the epidemic of shootings. She said Padgett’s parents "are ultimately responsible."

Meanwhile, school officials said they were going to go forward with previously scheduled plans to hold graduation on Thursday. There will be a candlelight vigil next Tuesday on the school’s football field.